Saturday, May 13, 2006

JSON (JavaScript Object Notation) is a lightweight data-interchange format. It is easy for humans to read and write. It is easy for machines to parse and generate. It is based on a subset of the JavaScript Programming Language. JSON is a text format that is completely language independent but uses conventions that are familiar to programmers of the C-family of languages, including C, C++, C#, Java, JavaScript, Perl, Python, and many others. These properties make JSON an ideal data-interchange language.JSON is built on two structures:1.A collection of name/value pairs. In various languages, this is realized as an object, record, struct, dictionary, hash table, keyed list, or associative array.2.An ordered list of values. In most languages, this is realized as an array, vector, list, or sequence.These are universal data structures. Virtually all modern programming languages support them in one form or another. It makes sense that a data format that is interchangable with programming languages also be based on these structures.

JSON's simplicity has resulted in its widespread use, especially as an alternative to XML in Ajax. One of the claimed advantages of JSON over XML as a data interchange format in this context is that it is much easier to write a JSON parser. In JavaScript itself, JSON can be parsed trivially using the eval() procedure. This was important for the acceptance of JSON within the Ajax programming community because of JavaScript's ubiquity among web browsers.